The Thirteenth Skull — Bonnie Ramthun

Discovering an ancient skeleton can be murder, as homicide detective Eileen Reed discovers when her parents ask for her help in a missing person's case. The missing man, an archeologist, has been excavating a Lakota buffalo jump at the Reed Ranch near Devil's Tower, Wyoming. The discovery of his murdered corpse and the treasure he took from the ancient skeleton are complicated further when a hired assassin targets Eileen's fiancé, Joe Tanner, a top-secret defense programmer. The big-city killers come to do murder in a small Wyoming town, and Eileen Reed finds herself in a fight for her life and the lives of her family, trying to solve a very personal murder and keep two very impersonal murderers from their intended slaughter. Her investigations include the mystery surrounding the flawless crystal skull unearthed from the arms of the Aztec warrior who died trying to deliver it to the Lakota tribe. The crystal skull exhibits mysterious properties that seem to defy explanation. Eileen must unlock the secrets of the skull in order to save her family from the killers and fulfill the Aztec's ancient mission.